MATHEMATICAL SCIENCES

The researchers mapped the most accurate rotation curve of the Milky Way to date


Schematic view of the Milky Way from top (left) and sideways (right) (Credit: NASA/JPL)

Recently, the research team of Huang Zhang, associate professor at the University of Chinese Academy of Sciences, and others used machine learning methods to accurately measure the rotation curve of the Milky Way within 16,000 light-years to 81,000 light-years from the center of the Milky Way. The results were published in the Journal of Astrophysics.

“This is currently the most accurate measurement of the rotation curve of the Milky Way.” The reviewers spoke highly of the results. The research results provide a crucial constraint for measuring basic physical quantities such as the total mass of the Milky Way and the density of dark matter in the solar field, which is of great significance for searching for dark matter particles and understanding the distribution of dark matter in the Milky Way

Accurately measuring the rotation curve of the Milky Way is quite challenging, and astronomers need to obtain accurate distance, proper motion, and radial velocity information for tracer objects farther from the center of the Milky Way. Huang et al. collected spectral data of more than 250,000 bright red giant stars in the Milky Way from China’s Guo Shoujing Telescope (LAMOST) and the US Galaxy Evolution Research (APOGEE) sky survey, which provided accurate parameter information such as star atmospheric parameters, line of sight speed, and chemical element abundance.

In addition, the research team further used the triangulation parallax in the ESA Gaia satellite data to obtain the spectroscopic distances of these more than 250,000 bright red giant stars from the spectral data. Various tests have shown that the estimation accuracy of these distances is better than 10%~15%, which is of great significance for accurately measuring the distance of stars in the farther reaches of the Milky Way.

Huang told China Science News that based on a large sample of the bright red giant, the research team selected about 54,000 thin disk stars of the Milky Way with apparent velocity, proper motion and spectroscopic distance, and constructed a galaxy rotation curve within 16,000 light-years to 81,000 light-years from the center of the Milky Way. Based on this rotation curve, the research team further constructed a mass model of the Milky Way. In this model, the researchers estimated the mass of the Milky Way to be about 805 billion times the mass of the Sun. (Source: Shen Chunlei, China Science News)

Related paper information:https://doi.org/10.3847/1538-4357/acadd9



Source link

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button